Clutch and starter



May 1l, 1954 l.. w. BIRBAUM 2,678,117

CLUTCH AND STARTER Filed May 1l, 1950 Enc-.INE I8 will :24

M 74 /f Fm-J. A-

INVENTOR. Lsfsa w. BmAUM BY vZ/MZ ATTORNEY Patented May 11, 1954 2,67891 UNITED STATES GFF-ICE Lester W. Bixbaum,` OconomowocfWisr,4 assign9rto LaBelle-Industries, Inc.; conomowcc-,-.Wis.f, a corporation of Wisconsinif 2" This invention relatest'o aclutchandstarter.` Another' objectisto' provide anassembly such An' object of` this invention is to provide a asfdes'cribed-finthe preceding paragraph wheresimple,` compact and rugged clutch and' starter in both of the clutches are speed responsive; assembly; Still another 'Objectis to-provide a clutchiand A further object is to provide ,a clutch and 5 starterassembly-fori useron'motorvehicles which starter assembly wherein a non-overriding prevents!free-wheeling. atspeeds-in excess of? a clutch delivers power in one direction andi' an predetermined maximum. overriding clutch delivers power inf another di-` Objects end-advantages otherthan those above rc'ction and the input side ofthe non-overriding set forth willibe". apparent from the following clutchis the output side of the overriding clutch description when read 11 ini connection with the and -vice versa, accompanying drawing which Another object is tc provide a compact' as-` Fig. 1 is apartly? schematic viewshowing a sembly including a centrifugal clutch for transcrosssection oftheclutchand starter mechamitting'power from a power source to a normally nismasusedin'driving a wheelb'y Vmeans of the driven device andastarterfor delivering power l5 engine; tothe 'power source from the driven device.` Fig. 2- islalcrosssectionfof the'startcr mecha Another object is toprovide' a compact devicey nism'"tale'en on line--Zotliig 1; having a unidirectionaloverriding starterfor' de- Fig. S'showsl thafstarter irifthe position occu# livering starting power from a normally driven pie'd-when the' wheel isdriving the engine; and unit toen engine anda centriugal clutciior 2o Fig. 4 shows the'starter position occupied when drivingly connecting the engineto the driven unit; overriddenbytheengine drive.

The illustratedembodiinent is particularly' de-4 the drawings` the clutchi and' starter assignedfor` use with motor bikes andsimilar vesembly transmits Dowerfromfengine Vlil 'to bicycle hicles, but it should be understood theapplica'- wheel* l2 through'centrifugal clutch iii) When' tionoi'the inventionis not limited to such"spe 25 desired,` the bicycle can' be peddled in the usual ciic' purposes. The' illustrated` form shows a" fashion to turn wheel I2 and feed power back centrifugalclutch' mounted` on afshaftor drivto the eng-inethrough unidirectional starter la' ingthe shaft when an enginerotates the-input untilth'e engine'startsi When the engine reside of. the clutch at a predetermined speed.' The tates the speed responsive clutch ifi at a speed shaft/"is `drivingly connected to the bicycle wheel. greater' than the speedofthe starter, the starter The clutch is'ncapable of. driving `romthe wheel is'overridden andiceases'` to function as a power to the engine for starting purposes. Therefore, feedback.

an overriding starteris provided for startingan'cl Enginel sheave IBl turns drive sheave 222i by to' .prevent free-wheeling above a predetermined means ofbeltl22': Sheave iisweided or brazed speed.' When the engine` starts, the starter is 35 ontheenlargeddiameterporticn 25ct sleeveii automatically overridden and the drive clutchbe` which' is" pressed on: bushing or bearing 28.- comes operative.` The drive clutch isspeed re- Bearing 28 is rotatably mounted on sleeve 23!g sponsive to permitthe engine to idle when thelbi'- welded on; orintegr'al with shaft k32. Therefore,

cycle is atrest and to prevent stalling the engine driv'esheaveA Zzand sleeve"A 26 are rotatable with dueto overload.f The starter, driven by the Wheel, 4D respectto' shaft 32 Di'shed drive plate 313 oi" the engages whenever rotating abe-ve apredetermined inp'ut side of "thecentrifugal clutch is welded or speed andlat a speed greater than theinputside brazed to the sleeved member 2t for rotation of the drive clutch, thus preventing free-wheeling therewith; A` plurality of hardened channels above the predetermined speed. aresecuredto the `inside face of drive plate Sfi- In view of the above remarks it will'be appren 45 to cooperatewith channels 38 on driven plate d6: ciated that afurther object of this invention is to'en'gage and guide balls' 62 and transmit rotato provide a compact, low-cost clutch' and starter n tional movement to thedriven plate. The inner suitable for use on motor bikes and similar've# ends or driven channels'. 38 are provided with' hicles. formed tongues 44. whichcooperateV with 'sleeve 2E Still afurther object is to provide aclutclian'dl' 50 to center driven plate and to serveas a. seat starterassembly wherein anon#overri`din,. r",cltchA for spring 46 compressed between the tongue and constitutes the normal drive from one p'owerinwasherwliretairiedon sleeve 26 by snap rin'gll. put or take-offdevice 'toanotherpowerinputor The tongues'alsoserve asyseat'sfor balls d2 when take-'off device' and an overriding clutch conthey are'move'fd'iin*tow'ardthe shaft by spring 416' stitutejs the drive means fromsaid other*device` 55 urgingthe 'driven plate 4'itowardlthe left; When' to"sad"one' device; theA inputisideoi the clutch `is rotatatv atl a *pre-i 3 determined speed, the balls 42 are thrown outwardly against the bias of spring 46 to force the drive plate to the right and sandwich friction disk 52 between the driven plate and output plate 54 welded on housing 5t. Housing EES and driven sheave 58 are xed on shaft 32. Therefore, when the input side of the clutch attains a predetermined slOeed, the clutch engages and drives sheave 58 and shaft 32 to turn bicycle wheel l2 by means of belt @El connected t wheel sheave 52.

At this point it will be appreciated that after the engine has been started the bicycle wheel will be driven upon the engine speed reaching that necessary to engage the centrifugal clutch. This clutch remains engaged as long as the engine speed is greater than the engaging speed. When the engine speed is decreased below the predetermined R. P. M. spring 4E will force driven plate iii to the left to disengage the clutch. This allows the bicycle to be stopped with the engine idling, thus avoiding stalling the engine at every stop.

Details of this drive clutch are shown and claimed in my co-pending application for Centrifugal Clutch, Serial No. 160,307, filed May 5, 1950.

To avoid the necessity of starting the engine by means of a rip cord or other means, this mechanism is provided with a starter for feeding power from the wheel to the engine. This starter comprises a unidirectional centrifugally responsive clutch including rotor 64 having a shaft portion 65 fitting within sleeve 3i] to drivingly engage the end oi shaft 32 by means of a conventional slot connection. The rotor is secured Vto shaft 32 by means of a headed bolt 68. 'I'he rotor has a Deripheral slot it and a cut-out portion l2. A peripherally slotted cylindrical roller 'M is positioned in rotor notch 'l2 where spring l@ urges the roller toward the center of the rotor. Spring l@ lies in peripheral slot 'IG in the rotor and passes through the slot in roller 'M This spring may be piano wire or the like and need not have great power. The spring is fixed on the rotor by means of stakes 'i8 driven through the rotor parallel to the shaft axis at a depth, with respect to the slot, suificient to crimp the spring as shown in Figs. 2 through 4. As may be seen in Figs, 2 through 4, a plurality of holes 8@ is provided for stake 18 so that the anchor point may be varied to change the spring rate. As the stake position approaches the free end of spring 16, the cantilever arm of the spring is shortened and the spring exerts a greater force opposing centrifugal force. As the spring rate is increased, the engaging speed of the starter clutch increases. With this construction the characteristics of a single spring may be varied to meet many needs. The stake is prevented from axial movement by means of disks 82, 84 on each side of the rotor.

The inside cf the belled or enlarged diameter portion 24 of sleeve 2t is provided with a complementary notch St adapted to receive weight 'M when it is thrown outwardly by centrifugal force. The belled member 2t is also provided with a slot 38 adapted to receive the free end of spring 'it to prevent damage thereto as would be occasioned with the spring if it were allowed to be bent.

When the starter is rotated in a clockwise direction (Figs. 2 through 4) the weight 'M will be thrown outwardly by centrifugal force when the predetermined speed is reached.V As the weight passes bell'notch 85 it is thrown into the ing the rate by varying the staking point toY change lthe cantilever characteristicsV of A 4the notch where it is immediately wedged between the generally radial edge of bell notch 86 and the inclined edge of the rotor notch 12, as illustrated in Fig. 3. This causes bell 24 to be picked up to rotate with the rotor. .Since drive sheave 2t is brazed on the bell, engine l0 will be driven. When the engine starts and the drive sheave speed exceeds the speed of shaft 32, the rotational speed of bell 24 in the clockwise direction is greater than the rotor speed. Therefore, the inclined surface of the bell notch 86 will force weight '1&5 back into the rotor notch to allow the bell 2li to override the starter. If the speed of the engine is increased to engage clutch |13, shaft 32 and the starter are driven by the engine. Assuming that there is no clutch slip, the starter does not drive or engage the bell since the speeds are the same. In practice, however, there is some clutch slip and the bell rotates faster than the starter and the starter is overridden.

From the above description it will be appreciated that the bicycle may be peddled until a predetermined speed is reached, at which time the starter engages to drive the engine and start the engine. This allows a desirable speed to be reached before taking on the engine load. When the engine is started, the unidirectional starter clutch is overridden and drive clutch I4 may be engaged by accelerating the engine to the engaging speed. rl'his insures that the engine speed is great enough to pick up the load, thus avoiding stalling the engine. To stop the bicycle the engine is decelerated below the engaging speed. It is to be noted that it is practically impossible to stall this engine since any excessive load tending to slow down and stall the engine disengages the centrifugal clutch before the stalling speed is reached.

Should the bicycle coast down a hill with the drive clutch engaged, it will be apparent that the bicycle does not free-wheel since the drive clutch remains engaged and causes the bicycle to work against the engine. -It will be noted that if the engine is decelerated while the bicycle is coasting down the hill, the clutch will remain engaged. Should the clutch slip under these conditions the starter will engage since its speed is greater than the speed of the input side of the clutch. If the clutch is disengaged and the bicycle coasts down a hill, the bicycle will free-wheel only so long as the starter (which is driven by the bicycle wheel) rotates at a speed below its engaging speed. However, upon the starter reaching its predetermined speed, it will engage 'and pick up the input side of the drive clutch (rotating at a speed less than the starter speed). This causes a direct drive back to the engine to prevent free-wheeling at high speeds. After the drive clutch has been engaged it cannot be overridden. The starter clutch is, of course, overridden upon the engine starting since the starter is unidirectional.

This clutch is extremely compact and is fabricated of simple parts which may be manufactured at low cost. All the parts employed are rugged and may be subjected to hard use without adverse eifects. The design permits of a wide range of operating characteristics with the same basic unit. Thus the engaging speed of clutch I4 may be varied by changing spring 45, by changing .theY size of balls 42, or by a combination of such changes. Similarly, the operating characteristics of the starter clutch may be varied by changing the rate of spring E5 per se or by Vchangspring. The weight of roller 14 may be changed to affect the engaging speed.

From the above description it will be appreciated that changes may be made without departing from the spirit of this invention. Therefore, this invention is to be limited only by the scope of the claim.

A clutch and starter comprising, a shaft, a member rotatably mounted on said shaft, a drive sheave fixed on said member and adapted to be driven by an external power source, a speed responsive centrifugal clutch mounted on said shaft, the input side of the clutch including a dished drive plate fixed with respect to said member and a cooperative driven plate free on said member, said plates being mounted in opposed, spaced relation, radially disposed, circumferentially spaced, complemental channel members mounted on the opposed faces of said plates, a plurality of balls movably disposed between said plates and Within said channels and mechanically coupling said plates for rotation in unison, said balls being movable radially outwardly within said channels under the influence of centrifugal force, spring means urging said cooperating plate towards said dished plate and in opposition to the action of centrifugal force on said balls, the output side of said clutch including a plate fixed on said shaft, a friction disk between said lastmentioned plate and said cooperating driven plate for transmitting power through the clutch to said shaft when said balls are thrown centrifugally outwardly to force said cooperating driven plate against the friction disk, and an overriding starter clutch rotatable with said shaft and including means operative to drivingly engage said member when said shaft is rotated at a speed above a predetermined speed and at a speed greater than the speed of said member.

References Cited in the file 0f this patent UNITED STATES PATENTS Number Name Date 1,678,638 Dunham July 31, 1928 1,859,334 Karle May 24, 1932 1,889,291 Pirinoli Nov. 29, 1932 2,357,284 Peterson et al Sept. 5, 1944 2,529,919 Cunningham Nov. 14, 1950 

